Field of the Invention
The present invention relates to a flexible display apparatus to which a flexible panel or electronic paper being freely foldable is applied, and more particularly, to a flexible display apparatus which can make an unfixed portion of the flexible panel or electronic paper slide using elasticity of the flexible panel or the electronic paper according to folding and unfolding of a hinge, thereby solving the problem that the central portion of the flexible panel or the electronic paper projects upwardly and soars up because the flexible panel or the electronic paper does not absorb a lengthwise change occurring by a circumferential change of the outer circumferential surface of the hinge when the hinge is folded or unfolded or that one end gets torn due to lack of elasticity when the hinge is folded.
Background Art
A display apparatus is an important part of electronic apparatus including an image device and a mobile communication device. Recently, flexible display means, such as a flexible panel or electronic paper, which is bendable and foldable, besides a conventional plate-type LCD panel, has been shown.
In order to apply such flexible display means to an image device and a communication device, a plurality of patents in relation with a winding type to store the flexible display means by winding using a roller and a folding type to store the flexible display means by folding at a folded part with a predetermined curvature have been disclosed.
Differently from the winding type, because the folding type does not need the roller and roller-related components, various patents of a method that an image display side is folded internally while facing each other like a notebook and flexible display means is fixed and supported on an inner face of a notebook case have been disclosed. However, such folding type display apparatuses have several disadvantages in that the problem causing a stepped portion on the image display side in a perfectly expanded state is not perfectly solved and in that the folded part is not protected from external force with constant curvature.
As another way of the folding type, Korean Patent Application No. 10-2008-0012667 discloses a multi-faced display using flexible display means adopting the method that the central portion is directly folded in a state where image display sides of flexible display means face an outer face and are opposed to each other. However, because the flexible display means lacking elasticity cannot absorb the lengthwise change at the portion corresponding to the circumferential length of a folded portion when the central portion is folded or unfolded, a sealed state may be damaged. So, Korean Patent Application No. 10-2010-0062787 discloses a mobile communication terminal with flexible display means to which a hinge is applied. In Korean Patent Application No. 10-2010-0062787, one end portion of the flexible display means is not directly fixed, but is varied in direction toward the inner face using a roller positioned inside an edge of the opposite side of the hinge, and then, a spring is applied to the end portion of the flexible display means varied in direction in order to absorb the lengthwise change.
However, due to the structural limitation that a constant tension by the spring is locally applied to one end portion of the flexible display means and the end portion is suddenly changed in direction and pulled using the roller, a sealed state of the flexible display means may be destroyed.
Moreover, because the circumference of unfixed end portion of the flexible display means causes friction with surrounding parts when the hinge is folded or unfolded, if the flexible display means is used for a long time, the sealed state may be damaged.
Furthermore, the single hinge is applied just to one end, but even if the application of the hinge is extended in such a way that hinges are applied to both sides of the edge, the application method is ambiguous and how to avoid mutual interference when the hinges are folded at the same time must be considered.
Additionally, due to the thin plate type body of the hinge, a user may feel inconvenient in use because the user must continuously grasp the flexible display means with the hand or use the flexible display means laying on a flat floor.
Differently from the mobile communication terminal with flexible display means to which the hinge is applied, Korean Patent Application No. 10-2012-0068710 discloses a flexible display device to which link members are applied instead of the hinge, so that the link members absorb the lengthwise change at the part corresponding to the circumferential length of the edge where folding is caused.
However, the flexible display device to which the link members are applied can exactly absorb the lengthwise change at the part corresponding to the circumferential length of the edge only when folding or unfolding of the link members is finished, and the link members are not always actuated at the same time but one of the link members is first actuated at random during the folding or unfolding process. Therefore, the flexible display device may damage the sealed state at the folded part during the folding and unfolding process.
Additionally, if different external forces are applied to a first supporter or a second supporter corresponding to a fixing body, differently from the hinge, the link members may be distorted and damage related components.
In addition, in a perfectly unfolded state, because the flexible display device does not have a part to properly block out light incident from the back of the central portion where the link members are located, there is a difference in color between both end portions and the central portion.